1. Field of the Invention
The present invention relates to multiple-input-multiple-output (MIMO) antenna systems, and particularly to complementary split ring resonator (CSRR)-loaded MIMO antenna systems, which provide compact antennas for radio frequency-based applications, including 4G cellular systems.
2. Description of the Related Art
The fourth generation (4G) wireless standards are made to meet the demands of high data rates required by current and future wireless services. Multi-input-multi-output (MIMO) antenna systems are an enabling technology that achieves high data rates in wireless mobile devices using wireless services.
MIMO antenna systems are made up by combining multiple antennas in the transmitter and receiver terminals of the wireless system. Although easier to implement at the transmitter side, which normally does not have strict limitation of size, the design of MIMO antenna systems at the receiver end (i.e., the user handheld terminals) is really challenging. This is due to the fact that most receivers are compact mobile devices with strict limitations on the size of the antenna. Due to these limitations, novel miniaturized antenna element designs are required.
To get good diversity performance of a MIMO antenna, it is necessary that the antenna elements be uncorrelated. This becomes a serious issue when the antenna elements are placed close to each other due to the size limitation of the MIMO antenna.
Thus, CSRR-loaded MIMO antenna systems solving the aforementioned problems are desired.